[wim]

Lenses are NOT shimmed for accurate focus. Lenses may be shimmed to get the focal length correct and the infinity point at infinity, but with AF it has... nothing to do at all. A lens which needs adjustments concerning AF accuracy on a certain camera (often referred to lens calibration) will not get "shimmed"

 

Case in point: a lens with an extension tube can focus just fine.

 

About the 6D vvs 5D mkII: Not only does the 6D have a much better noise profile, without the 5D mkII trademark noise banding, it ialso has a more accurate AF system with more AF settings, WiFi remote live view.

 

Lenses are shimmed for correct distance to sensor etc., and so that they indeed can achieve, amongst others, infinity focusing correctly. This has everything to do with focusing, and therefore with AF as well.

 

Lens calibration is just the electronic/digital part of the equation, to tell the AF system where to stop to get focus at the correct point. However, without an accurately "set" or shimmed lens, to make sure the lens plane is completely correctly aligned and has the correct distance to the sensor, and hence the AF system, that is often not possible. Lenses are not individually calibrated for mount distance, they are calibrated to a standard with a standard deviation, directly, electronically. In short, if shimming is not done correctly, they will not necessarily focus correctly, especially not with current dslr focusing systems (PDAF).

 

As to extension tubes: I guess you are joking. A lens plane still needs to be aligned correctly. And many lenses do NOT AF correctly with extension tubes. AF often is not precise enough for macro focusing. AFAIK, every manufacturer of macro lenses tells users to manually focus in close-up and macro situations, and not to rely on IS and/or AF.


As to the noise profile: I prefer the extra few MPs over the slightly lower oise, as indicated I rarely shoot over 1600 iso anyway. And 6400 iso is eminently usable on the 5D II, FYI. As to the "trademark noise banding": have you personally actually ever used a 5D II yourself and indeed have had any images ruined by it? I guess not. Funnily enough, never have I. I happen to have been shooting a 5D Mk II for 7 years now.

 

I think you may take certain comments on the internet too serious, every so often.

 

As mentioned before: in the end it is the photographer who creates the photograph, not the tool, i.e. camera, used to record an image.

 

Kind regards, Wim